Bobbins for use in weaving shuttles in the textile industry must be capable of handling a large variety of natural and synthetic yarns which, depending upon the particular yarn, can have a plurality of adverse effects on the life and operation of the bobbin. For example, wood bobbins which are used for some types of synthetic yarns must be able to withstand compressive forces that tend to cause crushing and splintering. Thus bobbins for use with these types of materials must be able to withstand greater forces than would ordinarily be encountered with most types of natural fiber yarns that possess lower tensile strengths. Additionally, with certain types of synthetics the abrasion of the bobbin is also aggravated and, further there is often left on the bobbin a tacky or rubbery coating that interferes with uniform payoff of the yarn from the bobbin. This latter difficulty is pronounced with yarns such as "Roto Set" yarns, which is a trademark for certain yarns produced by E. I. DuPont de Nemours and Company. These yarns are compact, multi-filament yarns wherein filament to filament spacing generally does not exceed one filament diameter and the filaments are generally intermingled.
Although, in the past, many types of surface finishes have been used to provide improved strengths, abrasion resistance and freedom from accreted filaments, only partial success has been achieved. U.S. Pat. No. 3,243,140 discloses certain coatings which are useful to solve some of the problems enumerated above, and this patent notes that conventional coatings such as lacquer, paint enamels, baked or unbaked varnishes, etc., have suffered operational limitations under certain conditions.
Further, in order to produce bobbins economically and expeditiously it is desirable that coating thicknesses be kept to a minimum and that drying time of the coatings be reduced to the lowest possible level and, further, that such drying be effected at ambient temperatures.